CD4 and cancer: Defining the epigenetic mechanism of cancer development enables targeted therapies to reverse genetic modifications and restore normal gene function [18].Immune cell infiltration correlation with PTGER1 expression was analyzed in KIRC and KICH using the TIMER database to evaluate infiltration levels of CD8+ cytotoxic T cells, CD4+ helper T cells, neutrophils, macrophages, and dendritic cells. In KIRC, a significant weak positive correlation was noted with CD4+ T cells.